Related Stories

Now, the true story has been made into the movie Adrift, starring Shailene Woodley and Sam Claflin as the central couple, which opens here tomorrow.

"I was surprised by my endurance," Woodley, 26, said at our interview at the Ritz-Carlton in Marina del Rey, California.

"We were working extremely long hours out on the open sea. Sam and I were losing quite a bit of weight as we weren't eating much. So not having the fuel to run you physically, along with the emotional complexities that were incredibly taxing at times, mixed with the physicality, it could have been a gruelling experience."

There was a particularly extreme diet the US actress and English actor Claflin, 31, had to follow as they both were required to lose weight.

"There was about a month of no dinner, which was difficult. It was a month of having a glass of wine before bed so I could just pass out and sleep. Then it was two weeks of a can of salmon and a couple of eggs and steamed vegetables, and that was it.

"I don't know that I could do it without Sam. We both really were there for one another in our moments of extreme exhaustion and hunger."

Woodley, an environmental activist, describes herself as a "water baby", saying she was born under water and has a deep affinity with it.

INSPIRED

"It is an element that I feel inspired by on an artistic level. Filming on the ocean, you learn how much you really are at the mercy of its power. You have to listen to your instincts about when to go with the flow and when to hang with the current and when to step back and say, 'These swells are too big and this undertow is too strong.'

"Doing this movie reinforced my appreciation and reverence for that, which we are so often disconnected to because of the distractions of the material world," said Woodley.

Best known for starring in The Divergent Series sci-fi film trilogy and romance drama The Fault In Our Stars, she could not stop crying when she read the screenplay as she knew nothing of the real-life tragedy prior.

She said: "There was an emotional attachment that I had to these two people that destroyed me in a way that no other script had emotionally."

Then she read Ashcraft's book and tried to watch every interview she had ever done.

Then they Skyped regularly and corresponded via letters, text messages and phone calls.

"It was really important to me as an actor and producer that her story be as authentically told as possible," said Woodley.

To that end, they did not make the story more dramatic because the actual events were dramatic enough on their own.

Ashcraft eventually came on the set for two weeks.

Woodley said: "In person, it hits you on a new level that you are not playing a character, you are portraying someone's truth.

"The most important thing to keep in mind that no matter how challenging or difficult our days were, the reminder that Tami herself went through this for 41 days, brought everything full circle and made us work even harder to protect the story."

The first day of filming Adrift was particularly rough.

"Everyone except for our director (Baltasar Kormakur) and cinematographer was gone. We had no hair and make-up that day, we had no sound that day, because everybody was in the cabin puking. Sam and I were both seasick all day long. It was a pretty miserable 12 hours.

"But as soon as we got back to shore, we all learned a valuable lesson of - if we are going to be spending this much time on a boat, what are the proper foods to eat?

"A lot of us just had coffee and went out to sea, and turns out it is not a great equation for sailing. So we took certain precautions and we had seasickness tablets, but it didn't take it away completely."

Shooting on the open ocean was part of Kormakur's plan, and everyone agreed to go along with it.

Said Woodley: "You would go from having no swell to 3m swells in five minutes. Then the winds would change and the clouds would roll out, and you would be in the sun with no wind whatsoever. You become completely at the mercy of Mother Nature when you are not filming on a sound stage, and that is what he wanted and I think you feel that in the movie."

It was an adventure she learnt to savour, and "the experience was so worth it".

"Every day felt like a new opportunity to learn something about myself. We had an incredible stunt team and marine safety team, but there were multiple times where I would get dropped in the ocean and they had to be 700 yards (640m) away or farther so they could get the wide shot they wanted.

"A shark could have come, a sea snake could have appeared. I was outside of my comfort zone 100 per cent. But I think in those moments, that is when you just rely on whatever it is that you choose to trust within yourself. And if a shark comes, I guess that is it,"Woodley said with a laugh.

Adrift also gifted her with something more.

While shooting it in Fiji, Woodley met her current boyfriend Ben Volavola, a Fijian rugby player for the Flying Fijians.

The couple made their red carpet debut at Adrift's Los Angeles premiere last week.

Speaking about him, she said: "So this movie is important for me in many ways. His rugby team was staying at the hotel we were at, that was how we met."